This is the Fat Shark ezHUF Head Tracker Data Cable. This 3.3' (1m) ezUHF Head Tracker Data Cable for the DominatorHD, DominatorV2, or Attitude V2 FPV headsets plugs into the PS/2 data port and passes head tracking control data from the Trinity 3-Axis Head Tracker Module to an ezUHF transmitter. It also can supply power to your headset from the transmitter. If multiple power sources are supplied at the same time, the headset will draw power from the highest voltage.